Mega2560 bootloader works once only

Using Arduino Microcontrollers
#1

I am creating a project which requires the power of an Arduino Mega2560 but in a restricted space. So I have built a board with the chip and all associated components required to reproduce the basics. I am loading the bootloader using the excellent procedure here... http://www.gammon.com.au/bootloader

The issue I'm having is that the bootloader works only once, the second time I attempt to use the normal serial programmer through a Sparkfun FTDI interface, it fails to communicate. I have seen comment in another thread that this is due to the fuses not being set properly... http://forum.arduino.cc/index.php?topic=288853.0

But I'm not sure what these should be set to or how does one go about changing the settings that are given by the bootloader process.

All this is a bit strange because a board I assembled a few months ago and bootloaded by the same process does not suffer the above problem.

Any help with this issue would be most welcome.

Andy Stephenson Oxford UK

#2

Andyone: I am creating a project which requires the power of an Arduino Mega2560 but in a restricted space. So I have built a board with the chip and all associated components required to reproduce the basics. I am loading the bootloader using the excellent procedure here... http://www.gammon.com.au/bootloader

The issue I'm having is that the bootloader works only once, the second time I attempt to use the normal serial programmer through a Sparkfun FTDI interface, it fails to communicate. I have seen comment in another thread that this is due to the fuses not being set properly... http://forum.arduino.cc/index.php?topic=288853.0

But I'm not sure what these should be set to or how does one go about changing the settings that are given by the bootloader process.

All this is a bit strange because a board I assembled a few months ago and bootloaded by the same process does not suffer the above problem.

Any help with this issue would be most welcome.

Andy Stephenson Oxford UK

See the latest few posts in THIS THREAD

#3

The main point of the other thread @Krupski pointed out, is an issue with the auto-reset circuit. So look at the auto-reset example diagram earlier in that thread.

#4

Many thanks,

Krupsky and hiduino, the problem was indeed in the reset circuit. After looking through the other thread it seems that this is the most common cause of this particular problem. The pullup resistor must have been faulty or not connected properly. I would have been chasing around a while before I found that one.

Nice one thanks once again.

Andy.

#5